A hypoid gear includes a first gear and a second gear that are held in mesh with each other. The first gear and the second gear comprise helical bevel gears, for example, and are held in mesh with each other such that their rotational shafts are offset from each other. Since the first gear and the second gear are held in mesh with each other, the rotary motion of the first gear can be transmitted to the second gear.
The hypoid gear produces gear noise due to a mesh-dependent transmission error. According to Patent Document 1, it has been proposed to measure transmission errors at various assembled positions (meshing positions) of the second gear and select a position with the minimum transmission error as the meshing position in order to reduce the gear noise.
Patent Document 1: Japanese Laid-Open Patent Publication No. 2002-310266